Phosphinate compounds prepared from acetylenic compounds and inorganic phosphite salts and derivatives of these compounds

ABSTRACT

An improved method is disclosed for the preparation of novel alkali metal diphosphinate salts by the reaction of an acetylenic compound with an alkali metal hypophosphite in the presence of a free radical source, the use of these novel compounds in further reactions to prepare diphosphonate compounds and diphosphinate containing adducts, oligomers and polymers and utilization of these compounds, polymers and oligomers to control calcium carbonate scale and mild steel corrosion in cooling water.

This application is a division of application number 08/235734, filedApr. 29, 1994, now U.S. Pat. No. 5,647,995.

BACKGROUND OF THE INVENTION

The present invention relates to a novel method for producing uniquephosphite salts.

INTRODUCTION

Additions of hypophosphorus acid and sodium hypophosphite to olefiniccompounds are well known but yields have not been good and sidereactions (telomerization, double addition, oxidation of hypophosphorusacid) occur. The reactions were frequently run under pressure andrequired long reaction times. Recently an improved method for additionof sodium hypophosphite to olefin was reported in U.S. Pat. No.4,590,014. This involved slow addition of the olefin and a free radicalsource in alcohol solution to an aqueous-alcohol solution of sodiumhypophosphite. Yields of 80% to 100% were reported for 1-olefins,cyclohexene and dimethyl maleate. The reactions required no pressureapparatus and were completed in five to eight hours in most cases.

THE DRAWINGS

FIGS. 1-3 show the preparation of several novel phosphinates using thesynthesis methods of the invention. Also shown are prior art reactionsof acetylenic compounds with inorganic acids of phosphorus. FIG. 4 showsthe preparation of novel polycarboxylic diphosphinate products.

PRIOR ART

Ethanediphosphonic acid (Reaction 1, FIG. 1) was prepared directly fromacetylene and phosphorous acid using U.V. light catalysis (Coleman,Monsanto). Nifant'ev, et al reacted acetylenic compounds withhypophosphorous acid and found that monoaddition of hypophosphorous acidwas the main reaction (Reaction 2, FIG. 1) even when 6 fold excess ofhypophosphorous acid was used. However, phosphinic acids added toacetylenes give both mono and diadducts (Reaction 3, FIG. 1). In thepresent invention, sodium hypophosphite was used and readily added toacetylenes to form diadducts in good yields.

THE INVENTION

The invention comprises in its broadest aspect:

a method for making compounds having the formula: ##STR1## and mixturesthereof where R and R' are radicals from the group consisting of H,alkyl, hydroxyalkyl, alkyl carboxylate, carboxyl, carboxylate,cycloaliphatic and substituted cycloaliphatic, phenyl and substitutedphenyl, and each do not contain more than 18 carbon atoms, x and y areintegers ranging from 0-2 with the sum of x+y being equal to 2, w and zare integers having a value ranging from 0-2 which comprises the stepsof reacting a compound of the formula:

    RC≡CR'

with at least two moles of sodium hypophosphite in the presence of polarsolvent soluble free radical catalyst and then recovering the producedcompounds.

These organodiphosphinic compounds as initially synthesized are in theform of mixtures of two easily recoverable compounds. These mixtures arerepresented by the formulas: ##STR2## with R and R' having the samevalues previously described.

The phosphinate compounds covered by the above formula are believed torepresent new compounds. This is particularly true with respect tocompounds where one occurrence R and R'0 are hydroxyalkyl groups whichcontain from between 3-12 carbon atoms. Typical of compounds readilyprepared by the process described herein and covered by the abovestructural formula would be those compounds where R' is either R or Hand R is a radical such as: ##STR3##

It is understood that the values for R & R' described above apply to thestarting acetylenic compounds and the organic phosphinates produced bythe method of the invention.

THE PREFERRED STARTING HYDROXYALKYL SUBSTITUTED ACETYLENIC COMPOUNDS

For a list of acetylenic alcohols that may be used in the process of theinvention to prepare several unique phosphinates reference may be had toTable 1.

                  TABLE 1                                                         ______________________________________                                        Acetylenic Alcohols                                                           Compound No.                                                                  ______________________________________                                         ##STR4##                                                                      ##STR5##                                                                      ##STR6##                                                                      ##STR7##                                                                      ##STR8##                                                                      ##STR9##                                                                      ##STR10##                                                                     ##STR11##                                                                     ##STR12##                                                                     ##STR13##                                                                    ______________________________________                                    

THE HYPOPHOSPHITE SALT

Sodium hypophosphite, which is employed in the present method as itsstable monohydrate, is the preferred hypophosphite salt for use in thepresent invention. When sodium hypophosphite is used as thehypophosphite salt, a sodium phosphinate will be isolated as thereaction product. Although it will generally be preferred that thepresent method be directed toward the preparation of sodium phosphinatesdue to their high water solubility, stability and low cost, for someapplications the preparation of other alkali metal or alkaline earthmetal phosphinates may be desirable. In such cases, other alkali metalhypophosphites such as lithium hypophosphite, potassium hypophosphite,rubidium hypophosphite, or cesium hypophosphite may be employed in thepresent reaction with the appropriate adjustment in the solvent system,reaction temperature and the like.

In the present method the molar ratio of acetylenic material tohypophosphite salt will be at least 1:2. Most preferably the molar ratioof acetylenic material to hypophosphite salt will use slightly more than2 moles of the hypophosphite.

THE FREE RADICAL INITIATOR

In the present invention a solution of the hypophosphite salt is treatedwith the acetylenic component in the presence of an amount of a freeradical source effective to catalyze the reaction between thehypophosphite anion and the acetylenic triple bond. Any of the commonfree radical sources including organic peroxides such as benzoylperoxide or diazo compounds such as 2,2'azobisisobutyronitrile (AIBN)may be employed in the practice of the present invention. Organicperoxyesters are the preferred initiators. Useful commercially availableperoxyesters include the alkylesters of peroxycarboxylic acids, thealkylesters of monoperoxydicarboxylic acids, the dialkylesters ofdiperoxydicarboxylic acids, the alkylesters of monoperoxycarbonic acids,and the alkylene diesters of peroxycarboxylic acids. Among these classesof peroxyesters the alkylesters of peroxycarboxylic acids and thealkylesters of monoperoxydicarboxylic acids are preferred in thepractice of the present invention. The former class of peroxyestersincludes t-butyl peroctoate, t-butyl perbenzoate and t-butylperoxyneodecanoate, while the latter class includes compounds such ast-butyl peroxymaleic acid. These compounds are commercially availablefrom Pennwalt Chemicals, Buffalo, N.Y. The amount of any free radicalinitiator required to catalyze the acetylenic-hypophosphite reactionwill vary depending upon the molecular weight of the initiator and itsthermal stability. In the case of the peroxyesters, mole ratios ofacetylenic to peroxyester of 10 to 1 or more have been found to provideacceptable reaction rates.

THE SOLVENT SYSTEM

In the practice of the present invention the solvent system can bechosen with the decomposition temperature of the reaction promoter inmind. A solution of hypophosphite is typically maintained at a constanttemperature while the acetylenic component and the free radicalinitiator are simultaneously added into the reaction vessel containingthe hypophosphite solution. Preferably the hypophosphite solution willbe maintained at a temperature at or slightly above the decompositionpoint of the free radical initiator compound. This temperature will beselected on the basis of the known decomposition temperature of the freeradical initiator compound and will preferably be established by meansof a refluxing azeotropic organic solvent system. The most commonlyemployed azeotropic solvent systems for use in the present invention aremixtures of alkanols and water. For example, mixtures of ethanol andwater within the range of about 2-8 parts ethanol to each part of watercan be compounded so as to reflux at temperatures of about 70-80 degreesC. A mixture of about 300 grams of reagent alcohol (a mixture of 95%denatured ethanol with 5% isopropyl alcohol) and 100 ml of water willreflux at a temperature of about 78 degrees C. Other organicalcohol-water systems may be selected which will reflux at temperaturesat or slightly above the decomposition points of organic peroxyestersuseful to initiate the present reaction, e.g. within the range of about50-100 degrees C. Other alcohols useful as the organic component of thepresent solvent systems include methanol, isopropanol, t-butanol and thelike.

GENERAL REACTION CONDITIONS

In the practice of the present invention the hypophosphite salt is firstdissolved in the organic solvent system and the solution brought to atemperature at or slightly above the decomposition point of the freeradical initiator compound. The acetylenic material and the free radicalinitiator are then slowly and simultaneously added to the heated,stirred hypophosphite solution. Preferably the acetylenic component andthe free radical initiator compound are dissolved in an organic solventwhich is the same as or is compatible with that used to dissolve thehypophosphite salt. Most preferably the acetylenic compound and the freeradical initiator will be added to the hypophosphite solution in adropwise fashion or could be added using a pump after having beencodissolved in the same solvent. However, separate solvent streams ofthe acetylenic compound and the initiator may be introduced into thehypophosphite solution so long as the introduction is substantiallysimultaneous. Once the organic compound and the free radical initiatorhave been introduced into the heated hypophosphite solution thetemperature of the reaction mixture, the combined solutions, ismaintained at or about the pre-selected temperature for a period of timeeffective to complete the reaction. For example, when a peroxyester isemployed to initiate the reaction of a terminal acetylenic or internalacetylenic compound with sodium hypophosphite the typical reaction timewill be within the range of about 1.5 to 10 hours preferably about 2 to8 hours. At the end of this reaction time the phosphinate salt isisolated simply by evaporating the solvents and drying the resultingsolid salt in vacuo. In some cases, usually with terminal acetyleniccompounds, the main product precipitated and was filtered off. Theextent of reaction between the hypophosphite and the acetylenic materialto form the phosphinate is easily determinable by ³¹ p NMR. The use ofthe preferred reaction times in the present method typically providesyields of phosphinate salts on the order of 55 to 100%. These yields areattained at reaction times which are one or two orders of magnitude lessthan those taught to be optimal by the prior art.

The present invention will be further illustrated by reference to thefollowing detailed examples.

EXAMPLE 1

In light of the known addition of hypophosphorus acid to acetylenes andthe improvement in yield and ease of reaction of sodium hypophosphiteadditions to olefins, it seemed possible that two moles of sodiumhypophosphite could be added to acetylenes. This reaction was expectedto go better with a terminal rather than an internal acetylene so thefirst reaction was attempted with methyl propiolate and two moles ofsodium hypophosphite in alcohol-H₂ O solvent as shown below. ##STR14##Tertiary butyl peroctoate (TBPO) initiator was used and the initiatorand acetylenic compound were dissolved together in denatured ethanol andadded over 2.5 hours to a denatured ethanol-water solution (2:1 wt.ratio) of sodium hypophosphite monohydrate. Heating at 80° C. wasmaintained throughout the addition and for 3.5 hours afterward. Duringthe addition and post heat, a precipitate was formed. At the end of thereaction the white solid precipitate was filtered off and dried in avacuum. This precipitate was identified by ³¹ p NMR as nearly puredisodium methyl 3,3-diphosphinicopropionate, the product resulting from1,1 diaddition of hypophosphite to the methyl propiolate triple bond.

EXAMPLE 2 Synthesis of Diphosphinic Compounds from Acetylenes

Additional diphosphinic compounds were prepared from a variety of commonacetylenes as shown in Table 2 and FIGS. 1-3 The same easy procedure wasused that was employed to react methyl propiolate with two moles ofsodium hypophosphite (Example 1) and as was described in the GeneralReaction Conditions section. In all cases t-butyl peroctoate (t-BPO)initiator and the acetylene were dissolved together in ethanol and wereadded slowly to a water-ethanol solution (usually 1:2 weight ratiorespectively) of sodium hypophosphite. All reactions were run at thereflux temperature of the ethanol-water azeotrope (80° C.). After theaddition was completed (2.5 -3.5 hours), heating at reflux was continued(4-10 hours).

In many of the hypophosphite-acetylene addition reactions, a precipitateof adduct formed as the reaction progressed. The precipitated materialresulting from hypophosphite addition to methyl propiolate (Example 1)was found to be only 1,1 adduct based on C-13 and P-31 NMR analysis.Unreacted sodium hypophosphite and possibly a little 1,2 adduct remainedin the filtrate. With the propargyl alcohol--NaH₂ PO₂ reaction (Example3), a fine precipitate formed which was difficult to filter. Phosphorus31 NMR analysis of this precipitate indicated that it was a mixture of1,1 and 1,2 adduct in about equimolar amounts. The filtrate contained asmall amount of organophosphorus compounds and was mostly unreactedsodium hypophosphite and other inorganic phosphorus compounds. In thereaction of sodium hypophosphite with 3,5-dimethyl-1-hexyn-3-ol (Example4) again the 1,1-adduct precipitated leaving a small amount of 1,2adduct and inorganic phosphorus compounds in the filtrate. With 1-hexyne(Example 6), the adduct that precipitated was again the product of1,1-addition with 1,2 adduct left in the filtrate, based on P-31 NMRanalysis. Reaction of two moles of sodium hypophosphite with2-butyn-1,4-diol (Example 5) did not result in precipitation of theadduct. Instead a two phase system formed with organophosphoruscompounds found in each layer. Both layers contained some 2,2 and some2,3-diadduct of hypophosphite to the butynediol triple bond. Reaction ofanother internal acetylenic bond compound, 3-hexyne-2,5-diol (Example7), with two moles of sodium hypophosphite also did not result inprecipitation of the adduct. No acetylenic compound was left when thereaction mixture was concentrated to dryness to obtain the product. The³¹ p NMR showed multiple P-H bond containing compounds present toonumerous to be identifiable. This result might be expected if both 3,3and 3,4 adducts were formed. With the 3,3 adduct, two asymmetric carbonsare present so that two pairs of diastereomers can exist. The 3,4 adductcontains four asymmetric carbons so that four pairs of diastereomers canbe present.

Although only a relatively few acetylenic compounds have been reactedwith two moles of sodium hypophosphite, some patterns of reactionbehavior were observed. For 1-alkyne compounds, the diphosphinic saltusually precipitates in the reaction medium (normally about 67 WT %ethanol-33 WT % water). The precipitating product is usually pure1,1-adduct or highly enriched 1,1-adduct, probably because 1,1-adductsare more polar and less soluble in ethanol-water than 1,2-adducts. Both1,1 and 1,2-diphosphinic adducts form but the 1,1-adduct is favored ifthe 2 carbon of the 1-alkyne is hindered as with3,5-dimethyl-1-hexyn-3-ol (Example 4) and methyl propiolate (Example 1).With internal acetylenic compounds 2-butyn-1,4-diol (Example 5) and3-hexyne-2,5-diol (Example 7)! both 1,1 and 1,2 type addition occurs andthe product mixture is soluble in the solvent.

Yields of these reactions were good, ranging from 60-100% based on theacetylenic compound. Increasing addition time of theacetylene-initiator-ethanol solution and increasing post additionholding time increased the yield in some cases. Reaction temperature wascontrolled by the reflux temperature of the water-ethanol azeotrope aswas described in U.S. Pat. No. 4,590,014. No other alcohols were triedbut these could be used if a different reaction temperature is desired.Since the alcohol-water reflux temperature determines the temperature ofthe reaction, a free radical initiator was chosen which decomposedconveniently at about 80° C. Tertiary butyl peroctoate has a half lifeof about 4 hours at 80° C. and use of t-butyl peroctoate resulted in thebest yields for addition of sodium hypophosphite to alpha olefins. Otherimitators such as Vazo 64, t-butylperoxymaleic acid, t-butyl perbenzoateand t-butyl peroxyneodecanoate may be used.

                                      TABLE 2                                     __________________________________________________________________________    PHOSPHINIC COMPOUNDS DERIVED FROM ACETYLENES                                   ##STR15##                                                                    EX.                                                                              ACETLYENIC COMPOUND                                                                        PHOSPHINIC COMPOUND                                                                             COMMENTS, YIELDS, ANALYSIS                  __________________________________________________________________________        ##STR16##                                                                                  ##STR17##                                                                                       ##STR18##                                      ##STR19##                                                                                  ##STR20##                                                                                       ##STR21##                                  1                                                                                 ##STR22##   CH.sub.3 O.sub.2 CCH.sub.2 CH P(O)(H)(ONa)!.sub.2                                               60% yield All 1,1 adduct, P-31 NMR                          NaO.sub.2 CCH.sub.2 CH P(O)(H)(ONa)!.sub.2                                                      Hydrolysis of Ex. 1                         3                                                                                 ##STR23##                                                                                  ##STR24##                                                                                       ##STR25##                                  4                                                                                 ##STR26##                                                                                  ##STR27##                                                                                       ##STR28##                                  6                                                                                 ##STR29##                                                                                  ##STR30##                                                                                       ##STR31##                                  7                                                                                 ##STR32##                                                                                  ##STR33##                                                                                       ##STR34##                                  8                                                                                 ##STR35##                                                                                  ##STR36##        76% yield                                   9                                                                                 ##STR37##                                                                                  ##STR38##        78% yield                                   10                                                                                ##STR39##                                                                                  ##STR40##                                                                                       ##STR41##                                  __________________________________________________________________________

EXAMPLE 3

A solution of 6.72 g of propargyl alcohol (Aldrich Chemical Co.) (0.12mole) and 1.5 g of t-butyl peroctoate dissolved in 35 g of denaturedethanol was added dropwise over a period of 3 hours to a stirredsolution containing 25.44 g of sodium hypophosphite monohydrate (0.24mole), 40 g of denatured ethanol and 20 g of deionized water. Thetemperature was maintained at 80° C. throughout the addition. After theaddition was completed, heating at 77-80° C. was continued for 3 hourslonger. During the addition and during the post heat, solidsprecipitated and began to stick to the reaction flask resulting inbumping during refluxing. The reaction mixture was left to cool and thefine precipitate settled to form a pasty mass on the bottom of theflask. The pasty product was filtered through a sintered glass funnelbut soon plugged the sintered glass and filtered very slowly. When athickened paste was obtained, the filter funnel and pasty precipitatewere placed in a vacuum oven and dried at about 50° C. and at 1 mm Hgvacuum for 24 hours forming a hard, white, hygroscopic, foamed solid,16.6 g. The filtrate was concentrated on a rotary evaporator and thenwas dried in a vacuum oven at 60° C. and at 1 mm Hg vacuum for 16.6hours. The dried product was a fluffy, brittle, white solid, 11.5 g.Total weight of the both products was 28.1 g, representing 100.9% yieldwhich indicates that some solvent was left on the solids.

Both portions of the reaction product were analyzed using ³¹ P NMR and¹³ C NMR. Interpretation of the NMR spectra indicated that both 1,1 and1,2 diadduct of hypophosphite with propargyl alcohol had occurred withthe precipitate containing more 1,1 adduct (disodium3-hydroxypropyl-1,1-diphosphinate) while the filtrate contained more 1,2adduct (disodium 3-hydroxypropyl-1,2-diphospinate) and unreactedhypophosphite. Overall yield of adducts was calculated to be 91% basedon ³¹ P NMR spectral data.

EXAMPLE 4

A solution of 12.6 g of 3,5-dimethyl-1-hexyn-3-ol (Aldrich Chemical Co.)(0.1 mole) and 1.5 g of t-butyl peroctoate dissolved in 35 g ofdenatured ethanol was added dropwise over 3.1 hours to a stirredsolution containing 21.2 g of sodium hypophosphite monohydrate (0.2mole), 40 g of denatured ethanol and 20 g of deionized water. Thetemperature was maintained at 80° C. throughout the addition. Aftercompletion of the addition, heating at 79-80° C. was continued for 4.8hours longer. A fine white precipitate formed in the reaction mixtureduring the addition and post heating. The reaction mixture was cooledand the precipitate was filtered off using a sintered glass funnel. Theprecipitate was washed on the funnel several times with fresh ethanol,air dried on the funnel for 2 hours and finally was dried in a vacuumoven at 1 mm Hg and 60° C. for 24 hours. Dry weight of the precipitatewas 21.8 g, a white solid. The filtrate was concentrated on a rotaryevaporator and then dried in a vacuum oven at 1 mm Hg at 60° C. for 22hours to leave 9.6 g of a brittle, puffy, white solid. The precipitatewas analyzed by ¹³ C and ³¹ P NMR and was identified as nearly puredisodium 3,5-dimethylhexyl-3-ol-1,1-diphosphinate, the product resultingfrom 1,1-diaddition of hypophosphite to the acetylenic bond of3,5-dimethyl-l-hexyn-3-ol. Phosphorous ³¹ NMR analysis of the driedfiltrate from the reaction showed that about half of it was unreactedhypophosphite and the remaining half was organophosphorous compounds,probably 1,2-diadduct of hypophosphite to the acetylenic compound.Neglecting organophosphorous compounds in the filtrate, the yield of themain product was 72.2%.

EXAMPLES 5-10

The reactions for Examples 5-10 were conducted using the procedures asdescribed for Examples 1-4. Results of these reactions are listed inTable 2. Acetylenic compounds used in these reactions were2-butyn-1,4-diol, 1-hexyne,2-hexyne-2,5-diol, 3-methyl-1-pentyn-3-ol,3-methyl-1-butyn-3-ol and 4-ethyl-1-octyn-3-ol.

Reactions with Diphosphinate Compounds

The novel diphosphinic compounds of this invention can be utilized toprepare novel diphosphonic compounds by oxidation of the diphosphinatesas shown in the following reaction and as illustrated by Example 11.##STR42## Similarly diphosphinate salt compounds from Example 3, Example4 and Example 6 were oxidized to form the corresponding diphosphonatesalt compounds using hydrogen peroxide (see Example 12, 13, 14). Thereaction products were analyzed by ³¹ P NMR which indicated that somedegradation had occurred during oxidation as shown by the presence ofsome ortho phosphate in the reaction mixture. Other oxidizing agentssuch as hypochlorite, bromine water, nitric acid, oxygen and the like,may be used with care in order to minimize degradation of thediphosphinate molecule.

The diphosphinate salt compounds of this invention can also be used aschain transfer agents in reactions with unsaturated carboxylic acids andsalts of chain length not more than 18 carbon atoms, such as maleicacid, acrylic acid, methacrylic acid, itaconic acid, citraconic acid,aconitic acid, crotonic acid and oleic acid. Polycarboxylicacid-diphosphinate salt adducts and oligomers result from thesereactions as illustrated by the reactions with acrylic and maleic acidin FIG. 4 and as described in Examples 15 and 16. A procedure similar tothat employed in U.S. Pat. No. 5,085,794 is utilized in the reaction ofmaleic acid with the diphosphinate compound as illustrated in Example15. Acrylic acid is reacted with the diphosphinate compound using aprocedure similar to that described in U.S. Pat. No. 4,239,648 (toCiba-Geigy) for reaction of acrylic acid with sodium hypophosphite.Ammonium persulfate initiator is used for the reactions of diphosphinatecompounds with both acrylic acid and maleic acid. Other common freeradical initiators, such as inorganic peroxides, hydroperoxides andazo-type initiators may be used.

As shown in FIG. 4, mixtures of products result from the reaction ofdiphosphinate salt compounds with unsaturated acids such as acrylic andmaleic acid. When the diphosphinate compound is a mixture of both 1,1and 1,2 diaddition products of hypophosphite, the reaction with acrylicacid produces a mixture of the two types of polymers shown in FIG. 4.Reacting the mixtures of diphosphinate compounds with 2 moles of maleicacid produces a complex mixture consisting of two types of 2:1 adductsof maleic acid and diphosphinate compounds and two types of oligomericproducts as shown in FIG. 4, based on ³¹ p NMR analysis.

Diphospinate salt compounds may also be used in condensationpolymerization reactions with formaldehyde (2 mole) and primary amines(1 mole) per mole of diphosphinate compound as shown in the generalreaction that follows: ##STR43## Reaction conditions are those which areused in the Irani phosphonomethylation reaction Moedritzer and Irani, J.O. C., 31 1603 (1966)!. Polymers that result from this reaction may havea wide variety of substituents on them depending on the substituentsfrom the primary amine used as well as those from the diphosphinatecompound. Example 17 illustrates this type of reaction in which glycine(NH₂ CH₂ CO₂ H) is used as the amine. Other common primary amines may beused such as alkyl amines of chain length not more than 18 carbon atoms,amino acids such as glycine, alanine, aspartic acid, glutamic acid,taurine, aminobenzoic acid, aminomethanesulfonic acid, sulfanilic acidand salts of the acids, ethanolamine, aniline, substituted anilines,cyclohexylamine, 6-aminocaproic acid, (aminomethyl)phosphonic acid andsalts and (aminoalkyl)phosphonic acids and salts.

EXAMPLE 11

A solution of disodium methyl 3,3-diphosphinicopropionate (Example 1) (5g., 0.0192 mole) and deionized water (11 g) was heated at 72° C. andhydrogen peroxide (35%) (4.11 g=1.438 g H₂ O₂, 0.0423 mole) (10% molarexcess) was added all at once. The solution was slowly heated to refluxover 2.5 hours, and was held at reflux for 9.5 hours longer. At the endof the heating period, the reaction solution was cooled and 50% sodiumhydroxide solution (4.615 g, 0.0577 mole) and 25 g deionized water wereadded. The solution was heated at 85-93° C. for 5 hours to saponify themethyl ester. Analysis of the resulting solution by ³¹ p and ¹³ C NMRindicated that the product was pentasodium 3,3-diphosphonopropionate.Concentration of the solution was 18.6%, calculated as disodium3,3-diphosphonopropionic acid.

EXAMPLE 12

A solution of disodium 3-hydroxypropyl-1,1-diphosphinate (Example 3)(5.0 g, 0.0216 mole) dissolved in deionized water (16 g) was heated to51° C. and hydrogen peroxide (35%) (4.61 g=1.613 g H₂ O₂, 0.0474 mole)(10% mole excess) was added all at once. The solution was heated toreflux over 25 minutes and held at reflux for 4 hours. At the end ofthis time, the solution was cooled and 50% sodium hydroxide (3.35 g,0.0419 mole) was added (to pH 13) to form the tetrasodium salt of3-hydroxypropyl-1,1-diphosphonic acid. Concentration of the solutioncalculated as the free diphosphonic acid was 13.9%. Analysis of thesample by ¹³ C and ³¹ p NMR indicated that some degradation had occurredduring oxidation.

EXAMPLE 13

A solution of disodium 3,5-dimethylhexane-3-ol-1, 1-diphosphinate(Example 4) (5.0 g, 0.0166 mole) dissolved in deionized water (17g) washeated to 50° C. and hydrogen peroxide (35%) (3.54 g=1.239 g H₂ O₂,0.0364 mole) (10% molar excess) was added all at once. The solution wasslowly heated to reflux over 2 hours and was held at reflux for 9.5hours longer. The solution was left to cool and 50% sodium hydroxide(2.0 g., 0.0250 mole) was added to pH 13 to form the tetrasodium salt of3,5-dimethylhexane-3-ol-1, 1-diphosphonic acid. Analysis by ³¹ P NMRindicated that all P-H bonds had been oxidized but some degradation hadoccurred. Concentration of the sample solution calculated as the freediphosphonic acid was 19.65%.

EXAMPLE 14

A solution of disodium 1,1-hexyl-diphosphinate (Example 6) (5.0 g,0.0194 mole) dissolved in 25 g of deionized water was heated to 80° C.in 10 minutes and hydrogen peroxide (35%) (4.15 g=1.452 g H₂ O₂, 0.0427mole) (10% molar excess) was added. The solution was heated to refluxand held at reflux for 14 hours. The solution was then cooled and 50%sodium hydroxide (2.9 g, 0.0363 mole) was added to pH 13 to formtetrasodium 1, 1-hexyl-diphosphonate. Concentration of the solutioncalculated as the free diphosphonic acid was 11.7%. Analysis of thesample by ³¹ P NMR indicated that most of the P-H bonds were oxidizedbut some degradation had occurred.

EXAMPLE 15

A solution of disodium 3-hydroxypropyl-1,1-diphosphinate (Example 3)(5.0 g, 0.215 mole) dissolved in deionized water (18 g) was heated to60° C. with nitrogen purging and to this was added a 33.84% solution ofmaleic acid (5.0 g., 0.0431 mole) prepared from maleic anhydride (4.22g, 0.0431 mole) dissolved in deionized water (10.56 g) over 2.5 hours.In a separate addition to the diphosphinate solution was also addedammonium persulfate solution (20%) (5g) over the 2.5 hour period.Heating at 60° C. was continued for 4.5 hours. Additional ammoniumpersulfate solution (10% solution) (2 g) was then added and heating at60° C. was continued for 3.5 hours longer. At the end of this time, thereaction solution was cooled and 50% sodium hydroxide (8.73 g, 0.109mole) was added to pH 13. Concentration of the resulting solutioncalculated as the disodium salt of the 2:1 adduct of maleic acid withthe diphosphinate was 19.72%. Analysis of the sample by ³¹ p NMR showedthe 70.8M% of the diphosphinic compound had reacted to give a complexmixture of oligomeric product and some 2:1 adduct in addition to 29.2 M% unreacted diphosphinic compound.

EXAMPLE 16

A solution of disodium 3-hydroxypropyl-1,1-diphosphinate (Example 3)(7.0 g., 0.0302 mole) dissolved in deionized water (15 g) was heated to60° C. With nitrogen purging, a solution of acrylic acid (4.34 g.,0.0603 mole) dissolved in deionized water (13.66 g) was slowly addedover 2 hours. In a separate addition but simultaneously, ammoniumpersulfate solution (9 g) (12.5% solution) was also added over 2 hours.Heating at 60° C. was continued for 3 hours longer before the reactionwas stopped and cooled. The reaction solution was analyzed by ³¹ p NMRand ¹³ C NMR and showed no unreacted acrylic acid. New phosphoruscompound peaks were found but not all diphosphinic compound reacted.Molecular weights of the polymer were found to be M_(n) 1420, M_(w)1820.

EXAMPLE 17

Disodium 3-hydroxypropyl-1,1-diphosphinate (5.0 g, 0.2155 mole),paraformaldehyde (95%) (1.361 g, 0.0431 mole), glycine (1.616 g. 0.0215mole) and deionized water (14.9 g) were added to a stirred reactor andheated to reflux. To this mixture was added concentrated hydrochloricacid (36.5%) (2.155 g, 0.0215 mole) and the mixture was heated at refluxfor 8.7 hours. The resulting solution was analyzed by ³¹ p NMR and wasfound to be a complex mixture of phosphorus compounds. Most of thestarting diphosphinic compound had reacted based on ³¹ p NMR analysis.

Usefulness of the Diphosphinates and Diphosphonates in CommercialApplications

The novel diphosphinates and diphosphonates of the invention have manyareas of usefulness. Those compounds containing at least one longaliphatic grouping are good detergents. In the area of industrial watertreating they can provide scale and corrosion inhibition to such systemsas boilers and cooling towers and in oil well process waters. Thepolycarboxylic acid-diphosphinate adducts/oligomers and polymers areuseful as dispersants and scale inhibitors in cooling towers andboilers, as dispersants for slurries of solids and as scale inhibitorsin oil well process waters. The diphosphinates and diphosphonates of theinvention can also be used as dental anticalculus agents and fortreatment of bone metabolism disorders.

To illustrate the ability of certain of the diphosphinates,diphosphonates and diphosphinate containing reaction products to inhibitscale and corrosion, the following examples are presented.

EXAMPLE 18 Evaluation Of The Diphosphinic Compounds as CaCO₃ ScaleInhibitors

1. CaCO₃ Scale Inhibitor Testing

Diphosphinate salt compounds prepared from acetylenic starting materialsand reaction products of diphosphinate salt compounds were evaluated asCaCO₃ scale inhibitors using a titration screening test describedgenerally in U.S. Pat. No. 4,457,847 or in U.S. Pat. No. 5,171,451.Results of these tests are shown in Table 3 expressed as saturationratios at given dosage levels. The saturation ratio indicates how manytimes above normal the solution has become supersaturated with CaCO₃before precipitation occurred due to the effect of inhibitor insolution. In Table 3, data for various dosage levels of the sample arelisted along with data for various reference inhibitors.

                                      TABLE 3                                     __________________________________________________________________________    CALCIUM CARBONATE INHIBITION DATA-TITRATION TEST                                                        Saturation                                          Example                                                                            Test                                                                             Compound          Ratios                                              No.  No.                                                                              Structure         5 ppm/10 ppm/15 ppm                                                                     Comments                                  __________________________________________________________________________    6    1  CH.sub.3 (CH.sub.2).sub.4 CH P(O)(H)(ONa)!.sub.2                                                60.8                                                                             85.4                                                                             100.8                                         4    2                                                                                 ##STR44##        -- 37.9                                                                             48.9                                                                              Contains phosphonic compounds.                 3  NaO.sub.2 C CH.sub.2 CH P(O)(H)(ONa)!.sub.2                                                     27.3                                                                             30.9                                                                             40.9                                                                              Example                                                                       1 hydro-                                                                      lyzed                                     3    4  HOCH.sub.2 CH.sub.2 CH P(O)(H)(ONa)!.sub.2                                                      16.1                                                                             22.5                                                                             20.7                                                                              1,2                                                                           adduct                                                                        also                                                                          present                                   7    5   CH.sub.3 CH(OH)CHP(O)(H)(ONa)!.sub.2-                                                          14.3                                                                             14.8                                                                             12.1                                                                              Some                                                                          3,3                                                                           adduct                                                                        present                                   5    6                                                                                 ##STR45##        10.6                                                                             14.8                                                                             15.6                                                                              Some 2,2 adduct present                            ##STR46##        45.4                                                                             -- --  Belclene 500, Ciba Geigy                          x + y = 16        65.2                                                                             -- --  Belsperse 161, Ciba- Geigy                __________________________________________________________________________

CaCO₃ Scale Inhibitor Testing of Phosphonate Compounds

Oxidation of the diphosphinate salt compounds to diphosphonate saltcompounds resulted in materials with improved calcium carbonate scaleinhibition. This is shown in Table 4 where the scale inhibition activityof the diphosphinate compound is compared to that of the correspondingdiphosphonate compound.

CaCO₃ Scale Inhibition of Phosphinate Compound Derivatives

Calcium carbonate scale inhibition activity of the diphosphinate saltcompounds is also improved by using them in polymerization reactionswith unsaturated carboxylic acids and in condensation reactions withamines and formaldehyde. The data in Table 5 shows that the propargylalcohol-dihypophosphite adduct (only the 1,1 adduct is shown but the 1,2adduct is also present in equal molar amount) has poorer scaleinhibition than the products made with maleic acid, acrylic acid and bycondensation with glycine. In Table 5 only the products made from the1,1-diphosphinate are shown but products made from 1,2-diphosphinate arepresent in equal amounts.

                  TABLE 4                                                         ______________________________________                                        CALCIUM CARBONATE INHIBITION DATA                                             DIPHOSPHINATE VS. DIPHOSPHONATE COMPOUNDS                                                                  Saturationn                                      Example                      Ratio                                            No.    Structure             5 ppm Dosage                                     ______________________________________                                        14     CH.sub.3 (CH.sub.2).sub.4 CH P(O)(ONa).sub.2 !.sub.2                                                80.0                                             6      CH.sub.3 (CH.sub.2).sub.4 CH P(O)(H)(ONa)!.sub.2                                                    60.8                                             12     HOCH.sub.2 CH.sub.2 CH P(O)(ONa).sub.2 !.sub.2                                                      77.9                                             3      HOCH.sub.2 CH.sub.2 CH P(O)(H)(ONa)!.sub.2                                                          16.1                                             11     NaO.sub.2 CCH.sub.2 CH P(O)(ONa).sub.2 !.sub.2                                                      40.9                                             1      NaO.sub.2 CCH.sub.2 CH P(O)(H)(ONa)!.sub.2                                                          27.3                                             13                                                                                    ##STR47##            56.6                                                     ##STR48##            37.9 (10 ppm)                                    ______________________________________                                    

                  TABLE 5                                                         ______________________________________                                        CALCIUM CARBONATE INHIBITION DATA                                             REACTION PRODUCTS OF DIPHOSPHINATE COMPOUNDS                                                                 Saturation                                     Example                        Ratio 5                                        No.    Structure of Compound   ppm Dosage                                     ______________________________________                                        3      HOCH.sub.2 CH.sub.2 CH P(O)(H)(ONa)!.sub.2                                                            16.1                                                  (Starting Material)                                                    15                                                                                    ##STR49##              58.0                                                  (Oligomeric products are                                                      also present.)                                                         16                                                                                    ##STR50##              48.9                                           17                                                                                    ##STR51##              28.6                                           ______________________________________                                    

EXAMPLE 19 Evaluation of Diphosphinate Salt and Diphosphonate SaltCompounds as Corrosion Inhibitors

Diphosphinate salt and diphosphonate salt compounds prepared fromacetylenic starting materials and reaction products of diphospinatecompounds were evaluated as mild steel corrosion inhibitors. Results ofthese tests are shown in Table 6. An electrochemical screening test wasused for this evaluation. The experimental section is as follows:

Experiments

In the experiments below, several tests were performed. These tests aresummarized as follows:

Saturation Ratio Test

A test solution is prepared by adding calcium, magnesium, inhibitor testpolymer and bicarbonate to deionized water. Initial concentrations ofthe salts should be: 360 ppm Ca⁺², 200 ppm Mg⁺², 500 ppm HCO₃ --(all asCaCO₃) and 5, 10, or 15 ppm of inhibitor test polymer as polymeractives/solids. The temperature is maintained at 140° F. (60° C.); thesolution is stirred at all times, and the pH is continuously monitored.The solution is titrated with dilute NaOH at a constant rate. With theaddition of NaOH, the pH of the test solution slowly increases, thendecreases slightly, and increases again. The maximum pH, prior to theslight decrease at precipitation, is the breakpoint pH. A mineralsolubility computer program is then used to calculate the calciumcarbonate supersaturation ratio based on test conditions at thebreakpoint pH. This supersaturation ratio is related to the calciumcarbonate inhibition performance. The test procedure is repeated fordifferent inhibitor solutions and dosages. All precipitated calciumcarbonate must be removed from the test apparatus with dilute HCl priorto the next test run.

The Saturation Ratio calculation is described in a paper entitled"Computerized Water Modeling in the Design and Operation of IndustrialCooling Systems" presented at the 41st Annual Meeting at theInternational Water Conference in Pittsburgh, Pa. Oct. 20-22, 1980. Thispaper is incorporated herein by reference.

The Saturation Ratio test is dependent on the formation of scale above acertain critical pH. Consequently, sodium hydroxide is added to the testsolution to increase the pH and supersaturate the test water until thebreakpoint pH is achieved. Nucleation and crystal growth occur duringthe test period. The breakpoint pH is used in a computer programdescribed in the paper above to calculate the saturation ratio values.This value is simply an index for predicting the tendency toward calciumcarbonate precipitation. The computer program calculates the saturationratio based on water composition, operating conditions, temperature,breakpoint pH, cycles of concentration, and acid pH control. The programalso compensates for temperature, ionic strength and ion pairingeffects. The greater the saturation ratio, the better the polymer is asa scale inhibitor.

Electrochemical Test

Both the Tafel plots and linear polarization resistance tests areconducted in the same water chemistry and conditions. The test solutionfor the electrochemical corrosion cell is prepared by adding calcium,magnesium, various inhibitors, and bicarbonate to deionized water toobtain 360 ppm Ca⁺², 200 ppm Mg⁺², 440 ppm HCO₃ (all as CaCo₃).Temperature is maintained at 120° F. and the solution is aeratedthroughout the test period. The pH is uncontrolled. A standard threeelectrode cell is assembled for the polarization studies. Pre-polishedmild steel specimens were used as the rotating working electrode, at aspeed of 500 rpm. All potential measurements are made against asaturated calomel reference electrode. Two graphite rods are used as thecounter electrode. Polarization resistance measurements are conductedwithin±20 mV of the corrosion potential at a scan rate of 0.1 mV/sec.Tafel plots are performed by polarizing the mild steel specimen at 20 mVcathodically and anodically from the corrosion potential.

The electrochemical test provides for measurement of Tafel plots andlinear polarization resistance data to measure corrosion inhibitionactivity. This activity is reported as a corrosion rate, and the lowerthe corrosion rate, the better the test compound is as a corrosioninhibitor.

Corrosion rates of 1 MPY or less are considered as necessary for goodcorrosion inhibition. All samples were evaluated in a formulationcontaining 10 ppm of the test compounds, 10 ppm ofphosphonobutanetricarboxylic acid (PBTC) and 15 ppm of a proprietarysulfonic containing polymeric dispersant-scale inhibitor. The data fromTable 6 shows that Example 7, 12, and 13 are effective as mild steelcorrosion inhibitors. The diphosphinate compounds, 3 and 4,corresponding to diphosphonate compounds 12 and 13 are poor corrosioninhibitors. Reaction of Example 3 diphosphinate compound with maleicacid (Example 15) and acrylic acid (Example 16) improved corrosioninhibition of the resulting oligomer or polymer but not enough to makethem good corrosion inhibitors.

                                      TABLE 6                                     __________________________________________________________________________    ELECTROCHEMICAL SCREENING TESTS                                               DIPHOSPHINIC AND DIPHOSPHONIC COMPOUNDS                                       Sam-                                                                          ple                      Corrosion                                            No.                                                                              Sample structure      Rate (mpy)                                                                          Comments                                       __________________________________________________________________________    Ex. 7                                                                              ##STR52##           0.834 3,4 isomer shown, 3,3 isomer                                                  also present.                                  Ex. 12                                                                            HOCH.sub.2 CH.sub.2 CH(PO.sub.3 Na).sub.2                                                          1.03  Sample also                                                                   contains 1,2                                                                  diphosphonate                                                                 compound.                                      Ex. 13                                                                             ##STR53##           1.22                                                 Ex. 3                                                                             HOCH.sub.2 CH.sub.2 CH(PO.sub.2 HNa).sub.2                                                         4.28  Sample also                                                                   contains 1,2                                                                  diphosphinate                                                                 compound.                                      Ex. 4                                                                              ##STR54##           5.53                                                 Ex. 15                                                                             ##STR55##           3.01  Sample contains oligomers and products                                        from 1, 2 diphosphinate isomer.                Ex. 16                                                                             ##STR56##           3.43  MW 1820, polymer pre- pared from 1,2-                                         diphosphinate isomer is also present.          __________________________________________________________________________     Test conditions:                                                              120° F., 500 rpm rotating specimen, water chemistry of: 360 ppm        Ca/200 ppm Mg/440 ppm HCO.sub.3.sup.-  (all as CaCO.sub.3), pH                uncontrolled, air agitation, mild steel specimen.                        

We claim:
 1. A method for making compounds having the formula: ##STR57##and mixtures thereof where R and R' are radicals from the groupconsisting of H, alkyl, hydroxyalkyl, alkyl carboxylate, carboxyl,carboxylate, cycloaliphatic and substituted cycloaliphatic, phenyl andsubstituted phenyl and each do not contain more than 18 carbon atoms, xand y are integers ranging between 0-2 with the sum of x+y being equalto 2, w and z are integers having a value ranging between 0-2 whichcomprises the steps of reacting a compound of the formula:

    RC≡CR'

with at least two moles of sodium hypophosphite in the presence of polarsolvent soluble free radical catalyst and then recovering the producedcompounds.
 2. The method of claim 1 where R is a hydroxyalkyl group andR' is R or H.
 3. The method of claim 1 where R is ##STR58## and R' is Ror H.
 4. The method of claim 1 where R is H or CH₃ (CH₂)mm=0-17) and R'is R or H.
 5. The method of claim 1 where R is carboxyl, carboxylate oralkyl carboxylate and R' is R or H.
 6. The method of claim 1 where R is##STR59## and R' is R or H.
 7. An organophosphonate comprising acompound having the formula: ##STR60## wherein R and R' are radicalsselected from the group consisting of H, alkyl, hydroxyalkyl, alkylcarboxylate, carboxyl, carboxylate, cycloaliphatic and substitutedcycloaliphatic, phenyl and substituted phenyl and each do not containmore than 18 carbon atoms.
 8. The organic phosphinate of claim 7 where Ris a hydroxyalkyl group and R' is R or H.
 9. The organic phosphinate ofclaim 7 where R is ##STR61## and R' is R or H.
 10. The organicphosphinate of claim 7 where R is carboxyl, carboxylate or alkylcarboxylate and R' is R or H.
 11. The organic phosphinate of claim 7where R is ##STR62## and R' is R or H.
 12. A method for making compoundshaving the formula: ##STR63## and mixture and salts thereof where R andR' are radicals from the group consisting of H, alkyl, hydroxyalkyl,alkyl carboxylate, carboxyl, cycloaliphatic and substitutedcycloaliphatic, phenyl and substituted phenyl and each do not containmore than 18 carbon atoms, x and y are integers ranging between 0-2 withthe sum of x+y being equal to 2, w and z are integers having a valueranging between 0-2 which comprises the step of oxidizing the organicphosphinate compounds of claim
 7. 13. An organophosphinate comprising acompound having the formula: ##STR64## wherein R and R' are radicalsselected from the group consisting of H, alkyl, hydroxyalkyl, alkylcarboxylate, carboxyl, carboxylate, cycloaliphatic and substitutedcycloaliphatic, phenyl and substituted phenyl and each do not containmore than 18 carbon atoms.
 14. The organic phosphonate of claim 13 whereR is a hydroxyalkyl group and R' is R or H.
 15. The organic phosphonateof claim 13 where R is ##STR65## and R' is R or H.
 16. The organicphosphonate of claim 13 where R is carboxyl, carboxylate or alkylcarboxylate and R' is R or H.
 17. The organic phosphonate of claim 13where R is ##STR66## and R' is R or H.
 18. The method for makingpolycarboxylic acid-diphosphinate salt adducts and oligomers by reactingunsaturated carboxylic acids and salts thereof of chain length not morethan 18 carbon atoms comprising acrylic acid, maleic acid, methacrylicacid, itaconic acid and oleic acid with the compounds of claim 7 using afree radical initiator.
 19. The method of claim 18 where the unsaturatedacid is acrylic acid or salts.
 20. The method of claim 18 where theunsaturated acid is maleic acid or salts.
 21. The method for makingcondensation polymers using the compounds of claim 7 by reacting themwith two moles of formaldehyde and one mole of primary amine per mole ofdiphosphinate compound under highly acidic conditions.
 22. The method ofclaim 21 where the primary amine is glycine, aspartic acid, glutamicacid or salts of the acids.
 23. The method of claim 21 where the primaryamine is taurine, aminomethanesulfonic acid, sulfanilic acid or salts ofthe acids.
 24. The method of claim 21 where the primary amine is(aminomethyl)phosphonic acid, (aminoalkyl)phosphonic acid or salts ofthe acids.